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Sponges and Cnidarians

Sponges and Cnidarians. Sponges. Sponges Intro. Origin. Evolution: believed to have evolved from protists Collar cells: are almost identical to many flagellated protist cells Uses of collar cells: Move water, ingest food and excrete waste. Sponges Intro, cont. Diversity.

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Sponges and Cnidarians

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  1. Sponges and Cnidarians

  2. Sponges

  3. Sponges Intro. • Origin • Evolution: believed to have evolved from protists • Collar cells: are almost identical to many flagellated protist cells • Uses of collar cells: • Move water, ingest food and excrete waste

  4. Sponges Intro, cont. • Diversity • Species #: 8300 • Variety: • 3% live in freshwater • Variety of shapes, sizes and colors • Live at a variety of sea depths

  5. Characteristics of Sponges • KingdomAnimalia • PhylumPorifera • They are mostly marine (live in salt water) • # of cells: multicellular (eukaryotic) • Body contains pores, canals and chambers that allow for water flow

  6. Characteristics of Sponges • Symmetry: radial • No definite head region • Interior surface: lined with collar cells (choanocyte) • Choanocyte: • a flagellated collar cell that lines the inner surface (mesophyll) of sponges

  7. Choanocyte • Beating flagella • Create water current • Capture food and water particles • Carries away waste

  8. Choanocyte • Collar is made of microvilli • Why? To create a filtering device to collect food

  9. Choanocyte • The food particles then become trapped • How? Taken in by the food vacuoles (where they are stored and digested)

  10. Actual Choanocyte at work

  11. Food and Oxygen Exchange • Efficient? Non-efficient? • Why? • Lots of collar cells working together

  12. Structure of a Sponge • Made of ? • Spicules – calcareous or siliceous, support structures • Spongin – fibrous proteins, made of collagen

  13. Spicules

  14. Spongin Fun fact: When you wash with natural sponges, this is the portion you wash/exfoliate with!

  15. Spicules & Spongin

  16. Characteristics of Sponges • Reproduce asexually or sexually • By? Budding or gemmules (asexual), sperm and egg (sexual) • Larva: motile, move • Adults: sessile, don’t move Sponge Love Scene #1 Sponge Love Scene #2 Sexual Budding

  17. Gemmule

  18. Three Main Body Types 1. Asconoid • Def: one large body cavity • Characteristics: • Collar cells line the main body cavity • Contain many pores

  19. Three Main Body Types 2. Syconoid • Def: many canals, water flows through each canal • Characteristics: • Collar cells line canals • Can filter more water

  20. Three Main Body Types 3. Leuconoid • Def: contains chambers • Characteristics: • collar cells line chambers • Often used for shower sponges

  21. Classification of Sponges • Kingdom: Animalia • Phylum: Porifera • Class Calcarea • Class Hexactinellida • Class Demospongiae

  22. Class Calcarea • Spicules • Made of calcium carbonate (like baking soda) • Shape: needle shaped, 3-4 sections/rays • Body types? • All three types represented

  23. Class Hexactinellida • Spicules • Made of? Silica (glass-like) • Description: Six sections/rays • Body types? Asconoid or leuconoid • Often called? • Glass sponges

  24. Class Hexactinellida

  25. Class Demospongiae • Spicules • Made of: silica • Description: don’t have 6 rays • Body types? Leuconoid only • Other characteristics: • Make up 95% of all sponges • Use this type in bath/shower

  26. Class Demospongiae

  27. Cnidarians

  28. Characteristics of Cnidarians • Kingdom Animalia • Phylum Cnidaria • Examples: • Hydra, sea anemone, jellyfish, Portuguese-man-o-war, moon jelly, sea pen, coral • Where do they live??? • Aquatic (mostly marine/salt-water)

  29. Characteristics of Cnidarians • Symmetry: Radial or biradial • Head region? No definite head region • Two basic types: • Polyp: tentacles facing upwards Ex: sea anemone, coral • Medusa: tentacles facing downwards Ex: jellyfish, man-o-war

  30. Polyp Form • Polyp – • Lifestyle of polyps? Sessile (do not move) • Body shape? Tubular (tube-like) • Mouth: Surrounded by tentacles (facing up)

  31. Medusa Form • Medusa – • Lifestyle? Mobile/motile (move) • Body shape? Umbrella shaped • Mouth : surrounded by tentacles that face downwards

  32. Life Cycle • Body forms? Most cnidarians exist as BOTH body forms at some point during their life cycle POLYMORPHIC • Reproduction • Polyp: reproduce asexually using budding • Medusa: reproduce sexually using sperm/egg

  33. Life Cycle

  34. Characteristics of Cnidarians • Two layered body • Epidermis – • Def: outer part of the body • Derived from? Ectoderm • Gastrodermis – • Def: inner part of the body • Derived from? Endoderm • Lines the gut cavity • Main function: digestion

  35. Characteristics of Cnidarians

  36. Characteristics of Cnidarians • Tentacles contain cnidocytes • Function: aid in capture of prey/food • Characteristics: armed with nematocysts • Nematocyst: stinging cell (contains hook/barb used to catch)

  37. Nematocyst • Stinging cells • Contain filament • When do they uncoil? When they are touched by animals (in the environment) • Contain barb or spine • Poisons can be injected

  38. Nematocysts Nematocyst Firing Nematocyst Firing

  39. Four Classes of Cnidarians • Class Hydrozoa • Class Scyphozoa • Class Cubozoa • Class Anthozoa

  40. Class Hydrozoa • Solitary (live as an individual) • Colonial (live in groups) • Reproduce? Asexually (Polyp form) OR sexually (medusa form) • Where do they live? Freshwater OR marine/salt-water • Examples: Hydra, Tubularia

  41. Hydra

  42. Obilia Medusa Polyp

  43. Physalia

  44. Class Scyphozoa • Movement: Solitary (live by themselves, but MOVE quiet a bit) • Body form: Medusa form (most) • Where do they live? All marine/salt-water • Organs? Sensory organs found on the ridge of the umbrella • Examples: Cassiopeia, Aurelia

  45. Aurelia

  46. Cassiopeia

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